A primer pair for amplifying part of the genome of all potyvirids by RT-PCR.

Sequence analysis was used to design a pair of degenerate oligonucleotide primers that amplified a 1.6-2.1 kbp fragment from the 3' end of the genome (virion protein gene and part of the NIb gene) of 17 species of the Potyviridae ('potyvirids'); 11 potyviruses, 2 bymoviruses, 2 macluraviruses, an ipomovirus and a rymovirus. The 'potyvirid primer 1' hybridizes to the 3' terminal poly-A region of the genome, and 'potyvirid primer 2' to the genomic region encoding the-GNNSGQ-motif of the NIb protein. Database searches showed that the potyvirid 2 primer is specific for potyvirids. Associated analyses indicated that the published amino acid sequence of part of the wheat streak mosaic rymovirus NIb protein is probably incorrect in part.